1. Field of the Invention
The present invention relates to a technology for preventing a leakage of personal information such as a telephone number while establishing a telephone call quickly and efficiently.
2. Description of the Related Art
Conventionally, when a user uses a telephone terminal such as a cellular telephone to make a call, the user dials a telephone number of a destination. To facilitate the dialing process, the telephone terminal is typically provided with functions such as a phonebook function, an abbreviated dialing function, and an outgoing/incoming call register function.
However, if the user looses the telephone terminal, personal information registered in these functions can be leaked and illegally misused by a malicious third party.
To solve this problem, Japanese Patent Application Laid Open No. 2002-261935 discloses a technology for generating a provisional telephone number corresponding to a regular telephone number. Thus, if a user notifies another party of the provisional number, the user can receive a call from the other party without notifying the regular number.
However, the conventional technology is inefficient because the user needs to notify the other party of the provisional number.
Moreover, the provisional number expires after a predetermined time duration to enhance security. Therefore, the user is required to take the trouble of notifying the other party of the provisional number each time he wants to receive a call.
Thus, it is imperative to devise a technology for preventing leakage of personal information such as telephone numbers while establishing telephone calls quickly and efficiently.